Nitrous Oxide Sedation Flashcards
Who discovered N2O
Sir Joseph Priestly
Who was the first person to consider N2O for dentistry, and is recognized as the discoverer of anesthesia
Dentist Horace Wells, used it on himself and reported no pain during tooth extraction
Who was the first anesthesiologist
Dr. T.G. Morton, an associate of Horace Wells
What is the blood gas solubility coefficient of Nitrous Oxide, and what does that tell us
.47
it tells you that it’s not very soluble in blood so it has a rapid onset and rapid offset
Because Nitrous Oxide leaves the blood so quickly it can cause increased pressure in closed spaces, what are certain complications this can cause
middle ear infections
bowel obstructions
pneumothorax
Indications for Nitrous Oxide
- when inhalation anesthesia is require
- used with volatile agents like halothane and ethrane
- in relief of severe pain (emergent situations) w/50% O2
- in short term painful procedures
- debridement and suturing
- in dental work to provide short-term anesthesia
- with 50% oxygen
Contraindications for Nitrous Oxide
- Not to be used when gas is entrapped within the body and where expansion might be dangerous
- head injuries with impairment of consciousness
- pneumothorax
- air embolism
- decompression sickness
- following scuba diving
- following air encephalography
- during myringoplasty
- gross abdominal distension
- intoxication
- maxillofacial injuries
- intraocular gas injections
What do we know about using Nitrous Oxide for patients who are pregnant or lactating
- N2O has been found teratogenic in rat embryos
- N2O hasn’t been found teratogenic in human embryos
- No absolute contraindications to its use in the first 16 weeks of pregnancy or breastfeeding, but use caution
What is diffusion hypoxia
when a patient is taken off of N2O, it leaves the blood and enters the alveoli and because it does so quite quickly it can dilute the concentration of O2 in the alveoli resulting in hypoxia
What are the symptoms of diffusion hypoxia
nausea, lethargy, headache, syncope
How can diffusion hypoxia be prevented
by administering 100% O2 for 5 minutes following termination of N2O
is it acceptable to administer N2O without an assistant present
No, Never because N2O can induce hallucinations and increase sexual arousal. So an assistant is necessary to make sure that nothing inappropriate happens, and verify that nothing inappropriate did happen.
Are we attempting to get our patients to stage 2 anesthesia when we use N2O
No, it can be dangerous
what are the symptoms of a patient who reaches stage 2 anesthesia with N2O
- deliria
- irregular vital signs
- vomiting
- breath holding (compromised airway)
What should we do if a patient reaches stage 2 anesthesia with N2O
Stop N2O immediately and give 100% oxygen on high flow (10 L/Min or more)
What are the effects of N2O on the cardiovascular system
it is an anxiolytic
- decreased heart rate
- decreased overall myocardial O2 demand
- decreased vascular resistance
- vasodilation
What are the effects of N2O on the pulmonary system
- Bronchodilation
is N2O safe to use on Asthmatic patients
yes, it is non-irritating, but can contribute to a reactive airway
is N20 safe to use on patients with emphysema, middle ear infections, or pneumothorax
no, it is contraindicated
What are the dangers of N2O
- long term exposure is related to neuropathy
- possible link to spontaneous abortion and decreased fertility in women
What is the purpose of the scavenging system with N2O
it prevents the N2O from diffusing into the room. it is a vacuum system that removes exhaled gasses and peripheral leakage of N2O.
Why should a patient not speak much while receiving N2O
- to prevent spreading the N2O into the room
- to increase the sedative effect on the patient
What colors are the O2 and N2O tanks
O2 tanks are green
N2O tanks are blue
How is Nitrous stored in the tanks
it’s both a liquid and a gas.
What must you be aware of when checking if an N2O tank is full or not
the gauge is not very reliable, it will show that the N2O tank is full as long as there is any liquid in the tank. so until the tank is about 25% full the gauge will continue to indicate that the tank is 100% full
how much more O2 will you need than nitrous
you will need about 2.5 times more O2 than N2O
